PostgreSqlExpression.cs

using System.Collections.Generic;
using System.Linq;

namespace ServiceStack.OrmLite.PostgreSQL
{
    public class PostgreSqlExpression<T> : SqlExpression<T>
    {
        public PostgreSqlExpression(IOrmLiteDialectProvider dialectProvider)
            : base(dialectProvider) {}

        protected override string GetQuotedColumnName(ModelDefinition tableDef, string memberName)
        {
            if (useFieldName)
            {
                var fieldDef = tableDef.FieldDefinitions.FirstOrDefault(x => x.Name == memberName);
                if (fieldDef != null && fieldDef.IsRowVersion && !PrefixFieldWithTableName)
                    return PostgreSqlDialectProvider.RowVersionFieldComparer;

                return base.GetQuotedColumnName(tableDef, memberName);
            }
            return memberName;
        }

        public override SqlExpression<T> OrderByRandom()
        {
            return base.OrderBy("RANDOM()");
        }

        protected override PartialSqlString ToConcatPartialString(List<object> args)
        {
            return new PartialSqlString(string.Join(" || ", args));
        }
    }

}